Basically, a solenoid valve serves as technical component for controlling the inlet or outlet of gases or liquids or performing open-loop or closed-loop control of the direction of flow. In particular in conjunction with solenoid valves which are used in motor vehicles, efforts have been made for some time now to ensure that they open as quietly as possible. However, the problem regularly arises that in a motor vehicle different types of solenoid valves can be installed in one valve arrangement, so that solutions for suppressing or reducing the generation of noise when the valves open have hitherto been designed as a function of the different types of solenoid valves.
Therefore, for example in the case of a TCS actuation system which has different types of solenoid valves, referred to as the “refresh pulse” which constitutes the energization which ensures that each solenoid valve is reliably opened, there is a preceding current profile which is intended to open the respective valve as quietly as possible in the pressureless state and is designed for this purpose as a function of different types of solenoid valves.
Said current profile is embodied in the manner of a current staircase and is illustrated schematically in FIG. 1. The current profile 4 is basically divided into a generally comparatively short actuation time 2 (also referred to as NVH (noise vibration harshness) pre-actuation), and a directly following full actuation time 3, wherein the actuation time 2 serves to open one or more valves of the valve arrangement as quietly as possible in the pressureless state, while during the full actuation time 3 it is to be ensured that the valve or valves is/are opened. In order to ensure this, the valve or valves is/are energized with a refresh pulse 5 at the start of the full actuation time 3. The refresh pulse 5 has a constant full actuation current 11 which is dimensioned in such a way that it is ensured that each type of solenoid valve of the valve arrangement can be reliably opened.
The current profile 4 is designed to be able to switch or to switch all the valves of the valve arrangement as quietly as possible with the full actuation current 11 before the refresh pulse 5. For this purpose, the current profile is staircase-shaped. The current profile 4 usually has a first step 6, a second step 7 and a third step 8. During the energization at the first step 6, the solenoid valve types are intended to open quietly with comparatively low opening forces. During the energization at the third step 8, the solenoid valve types are intended to open quietly with comparatively high opening forces. During the energization at the second step 7, the solenoid valve types are intended to open quietly with typical opening forces. In this context, the low and high opening forces are considered in comparison with the typical opening forces.